Assessing respondent-driven sampling: A simulation study across different networks

The purpose was to assess RDS estimators in populations simulated with diverse connectivity characteristics, incorporating the putative influence of misreported degrees and transmission processes. Four populations were simulated using different random graph models. Each population was “infected” using four different transmission processes. From each combination of population x transmission, one thousand samples were obtained using a RDS-like sampling strategy. Three estimators were used to predict the population-level prevalence of the “infection”. Several types of misreported degrees were simulated. Also, samples were generated using the standard random sampling method and the respective prevalence estimates, using the classical frequentist estimator. Estimation biases in relation to population parameters were assessed, as well as the variance. Variability was associated with the connectivity characteristics of each simulated population. Clustered populations yield greater variability and no RDS-based strategy could address the estimation biases. Misreporting degrees had modest effects, especially when RDS estimators were used. The best results for RDS-based samples were observed when the “infection” was randomly attributed, without any relation with the underlying network structure.     

新时代网络空间意识形态话语权的掌控策略

新时代网络空间意识形态话语权呈现出话语主体多元化、话语载体多样化、话语内容复杂化的新特点，也面临着国内网络空间意识形态话语权争夺日益激烈、国际网络领域西方意识形态话语权渗透交锋不断、我国网络空间意识形态话语权建设应对乏力等新挑战。要掌控新时代网络空间意识形态话语权，就必须提高话语主体素养以引导网络意见领袖发挥正能量，拓展话语载体多样性以提升主流意识形态话语权的影响力，坚持话语议题守正创新以打造社会主义意识形态优势话语，推进话语表达方式转换以实现中国话语标准的“国际化”。     

HIV/AIDS and other household shocks as catalysts of local commercialization of non‐timber forest products in Southern Africa

Local trade in non‐timber forest products (NTFPs) is increasing globally, yet the causes have been little studied. We examine household shock as a driver of NTFP trade in five southern African countries, with an emphasis on HIV/AIDS‐related illness and death. Over the past two years, 95% of trader households experienced at least one shock, with family illness and death recorded for 68% and 42% of households, respectively. Almost 40% had entered the trade because of HIV/AIDS‐related shocks. Additional shocks included natural disasters, crop pests or failure and livestock loss. The sale of NTFPs was the third most common coping strategy, after kinship and agricultural adjustments. Coping strategies differed between sites and type of shock.     

论生物安全法的风险防控机制

在风险社会背景下，生物安全法的风险防控机制旨在平衡现代生物技术研发应用、生态环境开发利用与生态保护和公共卫生安全保障之间的内在张力，体现并遵循生物安全法的价值理念。风险防控机制由风险评估、风险管理和风险沟通三方面组成，其有效运行需以科学判断的风险评估为前提，适度运用“成本-效益”分析手段，实现风险管理的最优化路径选择，并突破单向度的路径依赖，以实现全面的风险沟通。     

习近平新时代观的理论生成探讨

理顺习近平关于“中国特色社会主义进入新时代”的逻辑理路，有助于系统论证“新时代”的科学性和理论性。从方法论上看，习近平新时代观是应用马克思主义立场观点和方法得出的正确结论。从理论归因看，中国社会主要矛盾的转化作为习近平新时代观生成的主要标志，源于马克思主义关于矛盾运动的基本理论。从理论定位看，习近平新时代观展现的是中国发展的特殊阶段，内含着中国对自身发展的时代定位与目标趋向，渗透着中国与世界在共同发展中的新阶段、新高度、新未来，是对中国发展方向的顶层设计。     

“Filthy rich” and “dirt poor:” social and cultural dimensions of solid waste management (SWM) in Lagos

Abstract

This paper analyses how household solid waste was perceived and handled in traditional Yoruba and contemporary Lagos society in South West Nigeria. It highlights the roles of individuals, households, changing lifestyles and diet, business cycles, residential segregation, and state and non-state actors and institutions in waste management in Lagos. The filthy rich/dirt poor divide in Lagos is epitomised by spatial segregation and social stratification, reflected by contrasting highbrow neighbourhoods and massive dumpsites in the metropolis. Central to this discussion are changing economic dynamics. The boom years were characterised by conspicuous consumption, waste and replacement while economic adversity precipitated destitution, re-use and recycling of waste, and recourse to imported second-hand clothing and household utensils. The paper recommends a multi-pronged sustainable waste management strategy for Lagos.     

Maternal Employment,Community Contexts,and the Child‐Care Arrangements of Diverse Groups

Integrating family and child data from the Early Childhood Longitudinal Study–Birth Cohort with contextual data from the census, this study examined associations among maternal employment, aspects of communities related to child‐care supply and demand, and the early care and education arrangements of 4 year olds in Mexican‐origin, Black, and White families. Children with employed mothers were more likely to be in informal care arrangements than in early childhood education, regardless of racial/ethnic background. For children in Mexican‐origin families, selection into informal care over early childhood education was more likely in zip codes with greater demand for care as measured by higher female employment. Utilization of parent care versus early childhood education was also more likely for children in Mexican‐origin and Black families in zip codes with higher female employment. Constraints associated with maternal employment thus hindered children from enrolling in early childhood education, and community contexts posed challenges for some groups.     

Toward an emergent Asian behavioural model of perceived managerial and leadership effectiveness: a cross-nation comparative analysis of effective and ineffective managerial behaviour of private sector managers in India and South Korea

ABSTRACT

This Type 4 (emic-and-etic) indigenous cross-case/cross-nation comparative study compares the results of two Type 3 (emic-as-emic) indigenous replication studies of effective and ineffective managerial behaviour carried out within private companies in India and South Korea respectively. The method used was ‘realist qualitative content analysis’ involving inductive open and axial coding. Of the Indian findings 100% were found to be convergent in meaning with 94.43% of the equivalent South Korean findings. This has led to the identification of a two-factor emergent Asian behavioural model of perceived managerial and leadership effectiveness comprised of 16 positive (effective) and 6 negative (ineffective) generic behavioural criteria. These criteria could be used in both countries to critically review and improve extant, or develop new, competency-based management/leadership development programmes. The research findings lend no support to claims that national culture has a major impact on managerial and leadership practices, styles, and effectiveness.     

Optimal asset allocation for participating contracts with mortality risk under minimum guarantee

Abstract

We investigate an optimal investment problem of participating insurance contracts with mortality risk under minimum guarantee. The insurer aims to maximize the expected utility of the terminal payoff. Due to its piecewise payoff structure, this optimization problem is a non-concave utility maximization problem. We adopt a concavification technique and a Lagrange dual method to solve the problem and derive the representations of the optimal wealth process and trading strategies. We also carry out some numerical analysis to show how the portfolio insurance constraint impacts the optimal terminal wealth.